water pump 2005 8 HP

[gerryrichard]

Hi

Loking for some poosible help.
I have a 2005 8 hp yamaha 2 stroke. The pump works fine at RPM over idle but when I idle down the pump slows and water becomes hot.
I have replaced the pump and housing and all the lines are free and clear.
Could the connection from the top of the water pump housing not be seating into the supply line going up to the pee hole? its tough to see this when you slide on the bottom leg.
Any others thoughts would be appreciated.
Gerry

[gerryrichard]

Could it be a thermostat?

[gerryrichard]

Also the collar for the thermostat has been overheated and is melted?

[99yam40]

what is that made of?
had to get real hot to melt plastic but much more to do metal

[gerryrichard]

It is made from a hard plastic